Novel completion method for rigless intervention where power cable is permanently deployed

ABSTRACT

A submersible-pump assembly has an electric motor and pump adapted to be lowered into a string of production tubing. A permanently-deployed power cable is located in the annulus located between an outer surface of the production tubing and an inner surface of a string of casing. A set of wet-mateable power connectors provide electricity to the motor through hydraulically-actuated pins carried in hydraulic cylinders mounted to the outer surface of the production tubing. The power cable is connected to each pin for carrying electricity from the surface of the well to the pins. The pins are moved inward toward the motor to engage receptacles located in the outer surface of the motor. Alternatively, the power connectors may be a receptacle that receives a stab mounted to the tubing.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of Applicant's copending U.S.provisional application, Serial No. 60/236,485, filed on Sep. 29, 2000.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] This invention relates generally to downhole installations andrelates specifically to rigless interventions using electric motors andwet-mateable electrical connections.

[0004] 2. Description of the Prior Art

[0005] Submersible, downhole pumps are used to pump production fluidsfrom deep within wells to the surface when natural flow rates areinsufficient. A typical submersible-well-pump assembly comprises anelectric motor and a centrifugal pump attached to the motor. Normally,the pump and motor are secured to a lower end of a string of productiontubing. To provide electricity to operate the motor, a power cable isattached to the motor and sealed to prevent contact with the productionfluids or, in the case of subsea installations, contact with seawater.The power cable extends downward and is usually strapped to the exteriorof the production tubing for the entire depth of the installation. Whenthe pump assembly is removed for maintenance or other reasons, theproduction tubing and the power cable are also withdrawn. The removaland reinsertion of the power cable is difficult and causes wear on thepower cable. There have been proposals for permanently-deployed powercables, but these have had various disadvantages.

[0006] Therefore, a need exists for a system including apermanently-deployed power cable and providing electric power todownhole, submersible-pump assemblies having motors with conventionalconfigurations.

SUMMARY OF THE INVENTION

[0007] A submersible-pump assembly has an electric motor adapted to belowered into a string of production tubing and a submersible pumpmounted to the motor. A permanently-deployed power cable is located inthe annulus located between an outer surface of the production tubingand an inner surface of a string of casing. A set of wet-mateable powerconnectors provide electricity to the motor throughhydraulically-actuated pins carried in hydraulic cylinders mounted tothe outer surface of the production tubing. The pins in the powerconnectors are moved into engagement with receptacles in the pumpassembly to connect the power cable to the motor for carryingelectricity from the surface to the motor.

[0008] In a second embodiment, electrical connector pins are mounted tothe pump assembly. These pins are moved from a retracted position to anextended position in engagement with receptacles in the productiontubing. Hydraulic pressure extends and retracts the pins, the hydraulicpressure being supplied by pumping down the coiled tubing used to runthe pump assembly.

[0009] In a third embodiment, an arm extends from the inner surface ofproduction tubing and has a stab located near the inner end of the arm.The stab has circumferential, electrically-conductive bands that areconnected to the power cable i the annulus. The pump assembly has areceptacle for receiving the stab when the pump assembly is landed inthe tubing, the receptacle having contacts for engaging the bands on thestab.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The novel features believed to be characteristic of the inventionare set forth in the appended claims. The invention itself however, aswell as a preferred mode of use, further objects and advantages thereof,will best be understood by reference to the following detaileddescription of an illustrative embodiment when read in conjunction withthe accompanying drawings.

[0011]FIG. 1 is a schematic, cross-sectional view of a submersible-pumpassembly installed in a downhole location and constructed in accordancewith the present invention.

[0012]FIG. 2 is a schematic, cross-sectional view of an alternateconfiguration of a submersible-pump assembly installed in a downholelocation and constructed in accordance with the present invention.

[0013]FIG. 3 is a cross-sectional view of electrical connectingassemblies for use with the submersible-pump assemblies of FIG. 1 orFIG. 2.

[0014]FIG. 4 is an enlarged view of a portion of the connectorassemblies of FIG. 3, with the inner and outer connector assembliesshown prior to connection.

[0015]FIG. 5 is a cross-sectional view of the motor and connectorassemblies of FIG. 3, taken along the line V-V of FIG. 3.

[0016]FIG. 6 is a schematic, cross-sectional view of a second alternateconfiguration of a submersible-pump assembly installed in a downholelocation and constructed in accordance with the present invention.

[0017]FIG. 7 is a cross-sectional view of electrical connectingassemblies for use with the submersible-pump assembly of FIG. 6.

[0018]FIG. 8 is a cross-sectional view of a third alternateconfiguration of a submersible-pump assembly installed in a downholelocation and constructed in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0019]FIG. 1 shows an electric, submersible-pump assembly 11 installedin a downhole location. Assembly 11 consists of a pump 13, a sealsection 14, and a motor 15. A string of casing 16 is cemented to theinner surface of a borehole, and a string of production tubing 17 islocated within and generally coaxial with casing 16 to form an annulus18 between casing 16 and tubing 17. A packer 19, which may be a swabcup, is located at a lower end of production tubing 17 and lies betweencasing 16 and production tubing 17 to prevent production flow or otherfluids from entering annulus 18. A check valve 20 may be installed inthe lower portion of production tubing 17 to prevent fluid loss fromfluid flowing downward. Check valve 20 also allows for pressure-assistedremoval of assembly 11. An additional swab cup 21, or other type ofpacker, is located between pump 13 and the inner surface of productiontubing 17. Swab cup 21 is a lip seal and is preferably run with pumpassembly 11. Swab cup 21 allows upward flow past it, but preventsdownward flow. As pump assembly 11 is lowered, swab cup 21 slides on theinterior of tubing 17 and allows displaced fluid to flow past swab cup21.

[0020] Pump assembly 11 is assembled by securing a lower end of pump 13to an upper end of seal section 14 and securing a lower end of sealsection 14 to an upper end of motor 15. A running tool (not shown)releasably engages a neck 22 on the upper end of pump 13, productionfluids flowing out of neck 22, as in FIG. 1. The assembly 11 is thenlowered with the running tool on a line (not shown), such as coiledtubing or cable, through production tubing 17 until the desired depth isreached. The running tool and coiled tubing are then retrieved. To limiterosion of the inner surface of production tubing 17, neck 22 may be ofvarying length, as shown by the broken line in FIG. 1. The next timethat pump assembly 11 is retrieved for maintenance, it will be run inwith a neck 22 of different length than the previous run. Assembly 11passes through an orienting sleeve 23 and is rotated by engagement of ahelical shoulder 25 which rotationally aligns assembly 11 to therequired orientation for positioning within a no-go profile 27. Therunning tool may have a swivel, or other bearing, to allow assembly 11to rotate during installation without rotating the coiled tubing.

[0021] Three wet-mateable power connectors 29 are used to provideelectric power to motor 15. Outer connector assemblies 29 are affixed toproduction tubing 21 at 120-degree angular increments and may be locatedfully within annulus 18 or may slightly protrude within tubing 21. Eachouter connector 29 is connected to one conductor of a power cable 31that feeds electricity from a remote source to connector assemblies 29.Power cable 31 extends alongside and is strapped to tubing 17. Motor 15has a set of inner connectors 33 located in a depending lower section 35of motor 15 and positioned 120 degrees apart for mating with outerconnector assemblies 29. Outer connector assembly 29 is shown engagedwith inner connector 33.

[0022] Outer connector assemblies 29 may be hydraulically actuated, asdescribed below and shown in FIGS. 3 through 5, and may be of thegeneral design shown in U.S. Pat. No. 4,589,492 to Greiner, et al. Itcould also be of other types of retractable, wet-mateable design. Outerconnector assemblies 29 are connected to hydraulic lines 37,39,41 andare located a vertical distance from the lower end of production tubing17 that corresponds to the location of inner connector assemblies 33when motor 15 is installed in production tubing 17. Lines 37, 39,41 areconnected to a valve 43 that is electrically or hydraulically actuated.Valve 43 is connected to a hydraulic line 47 that provides pressuredistributed by valve 43 to lines 37,39,41. An accumulator may also bemounted downhole with valve 43.

[0023] Inner connector assemblies 33 are located within the housing ofmotor 15 and are tangent to a vertical outer surface of motor 15 as seenin FIG. 5. When hydraulic pressure is applied to outer connectorassemblies 29 by the position of valve 43, an outer insulator 45 in eachconnector 29 moves from a retracted position into engagement with innerconnector assemblies 33. A connector pin 49 is then moved from aretracted position and through outer insulator 45 to engage an innerportion of inner connector assembly 33 for making an electricalconnection insulated from seawater and production flow. To disconnectouter connector assemblies 29 from motor 15, hydraulic pressure is usedto cause outer insulator 45 and connector pin 49 to move to theirretracted positions. Because they are located in annulus 23, it isunnecessary to remove outer connector assemblies 29 and power cables 31when removing pump assembly 11.

[0024] Each outer connector assembly 29 has a hydraulic cylinder 51 orhousing mounted to the outer surface of production tubing 17. Outerinsulator 45 extends radially through a passage 53 in production tubing17, passage 53 intersecting the axis of production tubing 17 at a 90degree angle. As shown in FIG. 3, outer insulator 45 is a resilientmember that provides electrical insulation and has a convex, cylindricalsealing face 55 on its inner end. A passage 57 extends longitudinallythrough outer insulator 45 along the axis of outer insulator 45, andpassage 57 terminates in a slit 59 at sealing face 55. Slit 59 remainsin a closed position, as shown in FIG. 4, unless forced open.

[0025] A piston 61 is reciprocatingly carried in hydraulic cylinder 51,as shown in FIG. 3. Piston 61 is formed of electrical insulationmaterial, such as phenolic, and reciprocates between a stop 63 and theinner end of hydraulic cylinder 51. Hydraulic line 39 supplies hydraulicpressure to move piston 61 between the inner and outer positions. Line39 is connected to valve 43 which leads to a remote source of hydraulicpressure through line 47. The outer end of outer insulator 45 is securedto piston 61 for movement therewith. Piston 61 will move outer insulator45 from an outer or retracted position, generally as shown in FIG. 3, toan inner or extended position as shown in FIG. 5. In the retractedposition, sealing face 55 will be recessed within passage 53 and willnot protrude past the wall of passage 53.

[0026] Male connector pin 49 is reciprocatingly carried within passage57 of outer insulator 45. Connector pin 49 is a metal pin with a pointedtip 67 on its inner end. The outer end, as shown in FIG. 4, is rigidlysecured to a piston 69 carried in hydraulic cylinder 51 whichreciprocates between stops 63 and 73. Piston 69 is made of aelectrically non-conductive material. An electrical insulator extendsaround a portion of connector pin 49, and will contact inner piston 61when piston 69 is moved to the inner position in contact with stop 63.The movement of piston 69 causes connector pin 49 to move with respectto outer insulator 45 and extend past sealing face 55 through slit 59.

[0027]FIG. 4 shows an inner insulator 75 which is located within acavity 77 in motor 15 and contains an inner connector 79. Innerconnector 79 is preferably a female connector having a socket, a closedinner end, an open outer end and grooves or threads contained within.Insulator 75 and connector will remain permanently within motor 15.

[0028] A removable insulator 81 is also located in cavity 77 in motor15. Insulator 81 has a cavity 83 therein that has an axis that coincideswith the axis of inner connector 79 and, when pump assembly 11 isinstalled, with the axis of outer insulator passage 57. Cavity 83contains a dielectric fluid 85, which is preferably a silicon gel thatserves to prevent contact of electrically conductive liquids with theelectrical connectors. Cavity 83 has a central enlarged area 87 ofslightly larger diameter than the remaining portions of cavity 83.

[0029] A piston 89 is located in cavity 83, with its axis coincidingwith the axis of inner connector 79. Piston 89 is made up of aninsulating material that is soft enough to be penetrated by pointed tip67 of connector pin 49. Piston 89 has a diameter that is approximatelythe same as the diameter of cavity 83, but smaller than the diameter ofenlarged area 87, to allow dielectric fluid 85 to flow around piston 89when it is moved toward the connector.

[0030] A metal, electrically-conductive sleeve 91 is secured to theinner side of piston 89 for movement therewith. Sleeve 91 has a closedend on its inner end. The outer diameter of sleeve 91 is approximatelythe inner diameter of inner connector 79. The inner diameter of sleeve91 is approximately the outer diameter of connector pin 49. A flatrubber seal 93 extends across the outer face of piston 89 and is affixedwithin a recess 95 which is cylindrical and coaxial with cavity 83. Seal93 can be pierced by tip 67 of connector pin 49. Recess 95 has adiameter the same as sealing face 55 of outer insulator 45.

[0031] In operation, outer connector assemblies 29 will be attached tothe outer surface of production tubing 17, then tubing 17 will beinstalled in the well. Pistons 61, 69 will be in the retracted position.Sealing face 55 will be recessed within passage 53 in production tubing17, and tip 67 of connector pin 49 will be recessed within passage 57.

[0032] Submersible pump assembly 11, along with swab cup 21, is loweredthrough tubing 17 into place in the well, landing on no-go 27. Valve 43receives an electrical signal from the surface that causes hydraulicpressure to be supplied through line 39 to move piston 61 in each outerconnector assembly 29 inward, with hydraulic fluid being returned toanother line or to an accumulator. Each outer insulator 45 will moveinward, and sealing face 55 will enter recess 95 and abut against seal93. Well fluid within recess 95 will be purged from recess 95 by sealingface 55.

[0033] Then, another electrical signal is sent to valve 43 causinghydraulic pressure to be supplied through line 41 to push piston 69inward. Connector pin 49 will extend through slit 59 (FIG. 4), pierceseal 93, and begin pushing piston 89 to the left. As piston 89 moves tothe left, dielectric fluid 85 will squeeze into the interior of theconnector and will flow around the edges of piston 89, coming intocontact with the inner side of seal 93 and into contact with connectorpin 49. Piston 89 will continue to move inward, with sleeve 91 enteringthe interior of connector 79, to establish electrical contact betweeninner connector 79 and sleeve 91. When sleeve 91 is unable to move anyfarther inward, connector pin 49 will pierce piston 89 and enter theinterior of sleeve 91. This establishes electrical contact betweenconnector pin 49 and cable 31 and prevents the entry of well fluid intomotor 15. Stop 63 (FIG. 3) will prevent any farther movement inward ofconnector pin 49. Insulator 45 will be in abutment with piston 89,shielding connector pin 49 should leakage of well fluid into the housingoccur. Pierced seal 93 assists in preventing the entry of well fluid.The coiled tubing is unlatched from pump assembly 11 and retrieved. Whenpump 13 is operating, well fluids flow upward through check valve 20into the intake of pump 13 and are pumped up tubing 17. The three pinand insulator assemblies 45, 49 allow upward flow past them.

[0034] Submersible pump assemblies must be pulled periodically formaintenance and replacement. Coiled tubing with a retrieval tool is runback into the well and latched into the discharge neck 22. When removingpump assembly 11, the first step is to signal valve 43 to applyhydraulic pressure to line 39 (FIG. 3) to move connector pin 49 outward.Connector pin 49 will withdraw into passage 57, and slit 59 will closeto prevent well fluid from entering passage 57. Then, hydraulic pressureis supplied to line 37 (FIG. 3) to cause piston 61 to move outward. Thisretracts outer insulator 45, removing sealing face 55 from recess 95 andfrom passage 53. The running tool will be lowered to connect with neck22 of submersible pump assembly 11 and lift it through tubing 17 to thesurface. Tubing 17, electrical connectors 29, and power cable 31 remainin place. During maintenance, insulator 81, sleeve 91, seal 93, andpiston 89 are replaced with another unit filled with dielectric fluid85. The same connector pins 49 and insulators 45 can be actuated to makethe electrical connection.

[0035] In the event that sand or other sediments have built up aroundpump 13, it may be difficult to retrieve pump assembly 11 by pullingupward on the coiled tubing. If so, the operator may pump fluid down thecoiled tubing, which flows down neck 22 and out of the bottom of pump13. The fluid can not flow past check valve 20, therefore pressurebuilds up, tending to force pump 13 upward.

[0036]FIG. 2 shows an alternative embodiment of an electric, submersiblepump assembly 12. The general method of installation and powerconnection is the same for the inverted configuration of pump assembly12 shown in FIG. 2, but motor 15 is installed above seal section 14, andpump 13 is installed below seal section 14. Neck 22 is located on theupper end of motor 15 for grappling by the running tool (not shown).Connector assemblies 29, 33 are located a larger vertical distance fromthe lower end of production tubing 17. When pump assembly 11 isinstalled, a stinger 97 depending from the lower surface of pump 13stabs through a flapper valve 99, the production flow passing into pump13 through stinger 97. Flapper valve 99 is located in production tubing17 below assembly 12 and is used to open and close tubing 17.

[0037] A second alternate embodiment of the invention is illustrated inFIGS. 6 and 7. FIG. 6 shows an assembly 101 comprised of pump 13, sealsection 14, and motor 15 and assembled in the same orientation asassembly 11 in FIG. 1. Assembly 101 is installed within productiontubing 17, which is within and generally coaxial with casing 16. As inthe embodiments described above, a swab cup or packer 19 seals the lowerportion of annulus 18 between tubing 17 and casing 16. Also, a checkvalve 20 may be installed near the lower portion of production tubing17. Assembly 101 is suspended from head 103 by attaching the upperportion of pump 13 to the lower portion of head 103, head 103 beingsupported by no-go profile 104, a swab cup 105 being located above head103. Head 103 has three inner power connectors 106 that selectivelyengage outer power connectors 107 to provide electricity to motor 15,connectors 106, 107 being positioned in 120-degree increments. Unlikethe above-described embodiments, inner connectors 106 contain movablecomponents (FIG. 7), and outer connectors 107 are static. Outer powerconnectors 107 are connected to power cable 31, which extends from apower supply on the surface. Power cable 109 is connected to connectors106 and conducts power from head 103 to motor 15. Assembly 101 islowered into position on coiled tubing 111, which provides hydraulicpressure to operate inner power connectors 106.

[0038]FIG. 7 illustrates details of one embodiment of power connectors106, 107. Each inner power connector 106 comprises an inner insulator113 and a male connector pin 115. Insulator 113 and pin 115 areconnected to pistons 117 and 119, respectively, which arereciprocatingly carried within cylinder 121 of connector 106. Pistons117, 119 and insulator 113 are formed of electrical insulation materialin this embodiment. A slit 123 in insulator 113 allows pin 115 to passthrough the outer end of insulator 113. Pin 115 has a pointed outer end125 and an inner end 127 that is connected to power cable 129. Threeports 131, 133, 135 extend upward through the upper portion of head 103for providing hydraulic fluid to move pistons 117, 119 within cylinder121. Ports 131, 133, and 135 align with and sealingly engage passages137, 139, and 141, respectively, when a running tool 143 is attached tohead 103 during installation of assembly 101. Each port 131, 133, 135has a coupling 132 that sealingly engages a coupling 134 on one ofpassages 137, 139, 141. Couplings 132, 134 are of conventional designand preferably contain check valves to prevent leakage of fluid pressureand to prevent well fluids from entering head 103 or running tool 143.In FIG. 7, running tool 143 is shown detached from head 103.

[0039] Running tool 143, which is not part of this application, has alatch member that is hydraulically actuated to release pump assembly 101(FIG. 6) after it has landed. A retrieval tool has the same arrangement.One type of running tool has a chamber containing hydraulic fluid and apiston. The piston has one side in contact with the hydraulic fluid andthe other side in contact with water pumped down coiled tubing 111 forapplying pressure to the chamber. An output passage from the chamberleads to a valve section that selectively applies the pressure topassages 137, 139, 141 and a port leading to the unlatch mechanism. Thevalve section has a selector that shifts from one position to another inresponse to axial manipulation of the string of coiled tubing 111.

[0040] Other types of running and retrieval tools are feasible, such asones employing a separate hydraulic and/or electric line, run withcoiled tubing 111. The hydraulic and electric lines could be used tosupply pressure to passages 137, 139, 141 and operate the valves.

[0041] Outer power connector 107 extends through hole 145 in tubing 17at a position that aligns outer connector 107 and inner connector 106.Insulator 147 is located within hole 145, filling the outer portion ofhole 145, a recess remaining in the inner portion of hole 145. Insulator147 and hole 145 each have the same diameter as inner insulator 113. Aslit 149 extends through insulator 147, leading to receptacle 151.Receptacle 151 is attached to power cable 31 and is sized to receivepointed end 125 of pin 115.

[0042] In operation, casing 16 is cemented within a borehole. Outerconnectors 107 are installed in tubing 17, then tubing 17 is installedwithin casing 16. Running tool 143 is attached to coiled tubing 111(FIG. 6) and head 103 for lowering assembly 101 into the well, ports131, 133, 135 being sealingly engaged with passages 137, 139, 141.Pistons 117 and 119 are retracted to their innermost positions, theouter end of insulator 113 being nearly flush with the outer surface ofhead 103 and pin 115 being located fully within insulator 113. Slit 123is closed to prevent well fluids from entering insulator 113, and slit149 is closed to prevent well fluids from entering annulus 18. Assembly101 is lowered within tubing 17 until head 103 rests on no-go profile104 (FIG. 6).

[0043] After landing, hydraulic pressure is provided by pumping waterdown coiled tubing 111, which, due to the valves, forces hydraulic fluidthrough port 133 to force insulator 113 outward toward connector 107.The outer end of insulator 113 contacts the inner surface of insulator147 of connector 107, slit 123 aligning with slit 149 and well fluidsbeing displaced from hole 145.

[0044] The operator then shifts the running tool valves by stroking thecoiled tubing. Hydraulic pressure is then applied to the inner surfaceof piston 119 through passage 141 and port 135 by pumping water downcoiled tubing 111, moving pin 115 outward. Pointed end 125 moves throughslit 123 and through slit 149 and enters receptacle 151. Pin 115 carrieselectricity from power cable 31 to power cable 129, and cable 129conducts electricity to cable 109, cable 109 conducting electricity tomotor 15. When electricity is supplied to motor 15, motor 15 rotates toturn pump 13 to pump well fluids upward. After connectors 106 areengaged with connectors 107, running tool 143 is disconnected from head103 and removed from within tubing 17. To release, the operator strokescoiled tubing 111 again and then applies pressure through coiled tubing111. This forces hydraulic fluid to the latching mechanism and releasefrom pump assembly 101. To remove assembly 101 from within tubing 17,running tool 143 is reattached to head 103, and the installation processis reversed to disengage pin 115 and insulator 113 from connector 107.

[0045] A third alternate embodiment of the invention is illustrated inFIG. 8. Like those described above, assembly 151 comprises pump 13, amotor (not shown), and a seal section not shown). Tubing 17 is locatedwithin casing 16, and power cable 31 is located within annulus 18.Connector arm 153 is mounted to the inner surface of tubing 17 andconnects to power cable 31 through tubing 17. Electrical wires (notshown) within arm 153 conduct electricity from power cable 31 to threebands 155 located on stab 157. Stab extends upward from connector arm153 and has a pointed or rounded upper end. Bands 155 arecircumferential rings formed from metal, or other conductive materials,and are axially spaced apart from each other along stab 157. Thoughassembly 151 is illustrated with pump 13 at the lower end of assembly151, pump 13 may be located at the upper end of assembly 151 with themotor being at the lower end.

[0046] Assembly 151 also comprises a motor connector 159 located belowpump 13 and used for connecting a power cable 161 to bands 155 on stab157. Motor connector 159 contains contacts 163, which are preferablyspring-biased towards the center of motor connector 159, for contactingbands 155 when stab 157 is inserted into motor connector 159. Contacts163 protrude sealingly through inner wall 165 and are axially spacedapart by the same lengths as bands 155. Contacts 163 are connectedwithin motor connector 159 to power cable 161 by wires 167. Power cable161 extends upward to the motor, providing electricity for operating themotor. A wiper 169 is located in the lower end of motor connector 159for wiping well fluids from stab 157 as stab 157 is inserted. In analternative embodiment (not shown), motor connector 159 may be locatedwithin the motor when the motor is located at the lower end of assembly151.

[0047] In operation, assembly 151 is constructed with motor connector159 connected by power cable 161 to the motor, motor connector 159 beinglocated at the bottom of assembly 151. Connector arm 153 is mounted toproduction tubing 17, and tubing 17 is installed within casing 16.Assembly 151 is then lowered into production tubing 17 on a wireline orby other suitable means until stab 157 enters motor connector 159. Theweight of assembly 151 forces motor connector 159 onto stab 157, stabpassing through wiper 169 and forcing contacts 163 outward. Assemblymoves downward until fully seated on stab 157 and connector arm 153.When fully seated, contacts 163 are aligned with and contact bands 155.The operator provides electricity through power cable 31, theelectricity flowing through connector arm 153 to bands 155, then throughcontacts 163 and wires 167, then through power cable 161 to the motor.To remove assembly 151 from within tubing 17, assembly is connected to aline and pull upwards to disengage motor connector 159 from stab 157.

[0048] The advantages of using the present invention include the abilityto retrieve a submersible pump assembly without the need for withdrawingthe power cable, too. The cable is permanently deployed in the annulussurrounding the string of production tubing and is selectively connectedto the pump assembly using wet-mateable electrical connectors. Bypermanently deploying the power cable, the difficulty of removing thepump assembly and the wear and tear on the cable are both minimized.

[0049] While the invention has been shown in only two of its forms, itshould be apparent to those skilled in the art that it is not so limitedbut is susceptible to various changes without departing from the scopeof the invention. For example, only one power connector or band may beneeded when using DC power, the motor being grounded through the coiledtubing or production tubing. Power connectors may be operated by meansother than hydraulic pressure, for example, by electrical, pneumatic, ormechanical means. Also, various means of seating the motor connector onthe stab are available, including hydraulic or electric actuatorscarried in the motor connector.

We claim:
 1. A well pumping apparatus, comprising: a string ofproduction tubing located within a casing, defining a tubing annulusbetween the tubing and the casing; a submersible pump assembly having apump, an electric motor, and an electrical motor connector, thesubmersible pump assembly being dimensioned for lowering and retrievingthrough the tubing; a power cable located in the tubing annulus; and apower-cable connector mounted to the tubing and connected to the powercable, the power-cable connector making electrical contact with themotor connector when the submersible pump assembly motor is landed inthe tubing
 2. The apparatus of claim 1, wherein: the power-cableconnector comprises an arm extending inward from an inner surface of theproduction tubing and a stab extending upward from the arm, the stabhaving at least one conductor on an outer surface; and the motorconnector comprises a receptacle for receiving the stab, the receptaclehaving at least one contact for engaging the conductor on the stab. 3.The apparatus of claim 2, wherein: the stab comprises three conductors;and the receptacle comprises three contacts.
 4. The apparatus of claim1, wherein: the power-cable connector comprises three conductorsradially arrayed about an axis of the tubing in 120-degree increments;and the motor connector comprises three conductors radially arrayedabout an axis of the submersible pump assembly in 120-degree increments.5. The apparatus of claim 1, wherein: the motor connector comprises atleast one receptacle located on the submersible pump assembly; and thecable connector comprises at least one pin mounted to the tubing, eachpin being selectively moved from a retracted position into engagementwith one receptacle.
 6. The apparatus of claim 1, wherein: the motorconnector comprises a plurality of receptacles located on thesubmersible pump assembly; and the cable connector comprises a pluralityof pins carried by hydraulic cylinders mounted to the tubing, thehydraulic cylinders moving the pins from a retracted position intoengagement with the receptacles.
 7. The apparatus of claim 1, wherein:the cable connector comprises a plurality of receptacles located on thetubing; and the motor connector comprises a plurality of pins mounted tothe submersible pump assembly selectively moved from a retractedposition into engagement with the receptacles.
 8. The apparatus of claim1, further comprising: an orienting guide mounted to the tubing forrotating the submersible pump assembly to a selected orientation whilelanding in the tubing.
 9. The apparatus of claim 1, wherein: the motorconnector comprises a plurality of receptacles located on a connectorassembly extending downward from the motor.
 10. The apparatus of claim1, wherein: the motor connector comprises a plurality of pins mounted tothe submersible pump assembly selectively moved from a retractedposition into engagement with the receptacles, the motor connector beinglocated above the pump; and further comprising a lead extending from themotor connector to the motor for conducting electricity from the motorconnector to the motor.
 11. The apparatus of claim 1, furthercomprising: a running tool adapted to be secured to a running line andto the submersible pump assembly for lowering the submersible pumpassembly into the tubing, the running tool being releasable from thesubmersible pump assembly for retrieving the running line and runningtool after landing the submersible pump assembly.
 12. A well pumpapparatus, comprising: a submersible pump assembly having a pump, anelectric motor, and an electrical receptacle assembly, the pump andmotor being dimensioned for lowering and retrieving through a string ofproduction tubing; a power cable adapted to be strapped to an exteriorof the production tubing; and a connector-pin assembly adapted to bemounted to the tubing and connected to a lower end of the power cablefor providing electricity to the motor, the pin assembly having a pinthat is moved between a retracted position and an engaged position inengagement with the receptacle assembly,
 13. The apparatus of claim 12,further comprising: a hydraulic cylinder for moving the pin between theretracted and engaged positions.
 14. The apparatus of claim 12, wherein:the electrical receptacle assembly comprises three receptacles spaced120 degrees apart about an axis of the motor; and the pin assemblycomprises three pins adapted to be radially arrayed in 120-degreeincrements about an axis of the tubing.
 15. The apparatus of claim 12,further comprising: an orienting guide adapted to be mounted to thetubing for rotating the pump and motor to a selected orientation whilelanding in the tubing.
 16. The apparatus of claim 12, wherein: theelectrical receptacle assembly is mounted to a connector depending froma bottom of the motor.
 17. The apparatus of claim 12, furthercomprising: a running tool adapted to be secured to a running line andto the submersible pump assembly for lowering the submersible pumpassembly into the tubing, the running tool being releasable from thesubmersible pump assembly for retrieving the running line and runningtool after landing the submersible pump assembly.
 18. A method ofinstalling a pumping apparatus in a well, the method comprising: (a)mounting a power-cable connector and a power cable to a string of tubingand lowering the tubing into the well; (b) providing a submersible pumpassembly having a pump, an electric motor, and an electrical motorconnector; then (c) lowering the submersible pump assembly through thetubing; then (d) engaging the power-cable connector with the motorconnector when the motor is landed in the tubing
 19. The method of claim18, wherein: the power-cable connector comprises an arm extending inwardfrom an inner surface of the tubing and a stab extending upward from thearm, the stab having at least one conductor on an outer surface; themotor connector comprises a receptacle for receiving the stab, thereceptacle having at least one contact for engaging the conductor on thestab; and in step (d), inserting the stab into the receptacle, eachconductor engaging one contact.
 20. The method of claim 18, wherein: themotor connector comprises a at least one receptacle located on thesubmersible pump assembly; the power-cable connector comprises at leastone pin mounted to the tubing; and in step (d), selectively moving eachpin from a retracted position into engagement with one receptacle. 21.The method of claim 18, wherein: the motor connector comprise aplurality of receptacles located on the submersible pump assembly; thepower-cable connector comprises a plurality of pins carried by hydrauliccylinders mounted to the tubing; and step (d) comprises supplying fluidpressure to the hydraulic cylinders to move the pins from a retractedposition into engagement with the receptacles.
 22. The method of claim18, wherein: the motor connector comprises a plurality of pins locatedon the submersible pump assembly; the power-cable connector comprises aplurality of receptacles; and in step (d), selectively moving the pinsfrom a retracted position into engagement with the receptacles.
 23. Themethod of claim 18, wherein: step (c) comprises lowering the submersiblepump assembly on a line; and the method further comprising releasing theline from the submersible pump assembly and retrieving the line.
 24. Amethod of installing a pumping apparatus in a well, the methodcomprising: (a) mounting a power-cable connector and a power cable to astring of tubing and lowering the tubing into the well; (b) providing asubmersible pump assembly having a pump, an electric motor, and anelectrical motor connector; then (c) lowering the submersible pumpassembly through the tubing on a running line; then (d) moving pinscontained in one of the power-cable connector and the motor connectorinto engagement with the other of the power-cable connector and themotor connector when the motor is landed in the tubing; then (e)releasing the running line from the submersible pump assembly andretrieving the running line.
 25. The method of claim 24, wherein: step(b) further comprises providing the submersible pump assembly with afirst discharge tube of a first selected length above the submersiblepump assembly; the method further comprising retrieving the submersiblepump assembly through the tubing for maintenance and replacing the firstdischarge tube with a second discharge tube of a second selected lengththat differs from the first selected length; and reinstalling thesubmersible pump assembly in the tubing.
 26. The method of claim 24,wherein: step (c) comprises installing a swab cup above the submersiblepump assembly, the swab cup restricting the upward flow of fluid in theproduction tubing past the swab cup and preventing fluid from flowingdownward past the swab cup; and installing a check valve in the tubingbelow the submersible pump assembly the check valve allowing fluid toflow upward through the check valve and preventing downward flow throughthe check valve.
 27. The method of claim 26, further comprising:reattaching the running line to the submersible pump assembly forretrieving the submersible pump assembly; and pumping fluid downwardthrough the running line and through the pump to cause a fluid pressurebetween the swab cup and the check valve, the pressure applying upwardforce on the submersible pump assembly to assist in retrieval.